.book .book-summary .chapter>.articles {
    overflow: hidden;
    max-height: 0px;
}

.book .book-summary .chapter.expanded>.articles {
    max-height: 9999px;
}

.book .book-summary .exc-trigger {
    position: absolute;
    left: 12px;
    top: 12px;
}

.book .book-summary ul.summary li a,
.book .book-summary ul.summary li span {
    padding-left: 30px;
}

.book .book-summary .exc-trigger:before {
    content: "\f105";
}

.book .book-summary .expanded>a .exc-trigger:before,
.book .book-summary .expanded>span .exc-trigger:before {
    content: "\f107";
}